Peterborough maternity services welcomed 158 girls and 183 boys, with two sets of twins arriving.
The majority of births were on the maternity unit at Peterborough City Hosptial (PCH), with 36 babies born in the midwifery-led birthing unit, four born at home and 12 women opting for water births.
The busiest day for births came at the end of the month, with 17 babies born on May 29.
Emergency C-sections accounted for 15.2% of births. Elective C-sections comprised 16.6% and 8% were assisted births.
The level of one-to-one care reached, when a woman is cared for by a midwife who is only looking after her, was 99.3%, slightly up from April.
The graphics shared by North West Anglia NHS Foundation Trust's maternity service Facebook page also include Hinchingbrooke Hospital, with 167 babies born in the Huntingdonshire hospital.